/Engine/Source/Editor/UnrealEd/Public/Kismet2/BlueprintEditorUtils.h
Returns the graph's top level graph (climbing up the hierarchy until there are no more graphs)
The top level graph
static [UEdGraph](API\Runtime\Engine\EdGraph\UEdGraph) * GetTopLevelGraph ( const [UEdGraph](API\Runtime\Engine\EdGraph\UEdGraph) * InGraph )